Animal resources welfare minister Anisur Rehman said the districts bordering Bangladesh have been alerted so that chickens are not brought in from that country.

``Chicken is not usually brought from Bangladesh. But under present situation, it is possible that it could be brought in at a cheap rate. We are trying to prevent that,'' he said.

The alert came following reports of chickens' death in the Aziz Poultry Farm near Siliguri in North Bengal in the last three-four days.

The poultry where at least 2,300 chickens have been died has been sealed. Rehman said he was not ruling out bird flu at Aziz Poultry Farm.

``Samples have been sent to Bhopal's Animal Diseases Diagnostic Laboratory and nothing can be said until we get the report. Prima facie, it appears to be gamboro or ranikhet disease,'' he said.

West Bengal Poultry Farm Welfare Association (WBPFWA) vice-president Manoranjan Naskar, however, said, ``Bird flu has never broken out in the state and I don't think it is any different this time. Casualties may happen due to Ranikhet and it's inevitable. Our safety measures are adequate.''

No safety measures, however, have been recommended for the farms. The animal husbandry department said some of them are at risk for they rarely followed the safety norms.